Mobile communication is the provision of voice, data, and other wireless services to portable electronic devices that may move about freely rather than stay fixed in a single location. Mobile telephones connect wirelessly to land-based cellular networks of base transceiver stations that link to a public switched telephone network to allow any telephone in the world to be dialed. Mobile telephones send and receive radio signals with any number of cell site base transceiver stations fitted with microwave antennas. These sites are usually mounted on a tower, pole or building, located throughout populated areas, then connected to a cabled communication network and switching system. The mobile telephones have low-power transceivers that transmit voice and data to the nearest cell sites. The mobile telephone has transitioned from being an expensive item used by the business elite to a pervasive, personal communications tool for the general population. In most countries, mobile telephones outnumber land-line phones and have become important components of the society's contemporary culture. The use of mobile phones by people who are driving has become increasingly common, either as part of their occupation or for talking with family or friends.